1 // Debugging iterator implementation (out of line) -*- C++ -*- 2 3 // Copyright (C) 2003-2015 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the 7 // terms of the GNU General Public License as published by the 8 // Free Software Foundation; either version 3, or (at your option) 9 // any later version. 10 11 // This library is distributed in the hope that it will be useful, 12 // but WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 // GNU General Public License for more details. 15 16 // Under Section 7 of GPL version 3, you are granted additional 17 // permissions described in the GCC Runtime Library Exception, version 18 // 3.1, as published by the Free Software Foundation. 19 20 // You should have received a copy of the GNU General Public License and 21 // a copy of the GCC Runtime Library Exception along with this program; 22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 // <http://www.gnu.org/licenses/>. 24 25 /** @file debug/safe_iterator.tcc 26 * This file is a GNU debug extension to the Standard C++ Library. 27 */ 28 29 #ifndef _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 30 #define _GLIBCXX_DEBUG_SAFE_ITERATOR_TCC 1 31 32 namespace __gnu_debug 33 { 34 template<typename _Iterator, typename _Sequence> 35 bool 36 _Safe_iterator<_Iterator, _Sequence>:: _M_can_advance(const difference_type & __n) const37 _M_can_advance(const difference_type& __n) const 38 { 39 if (this->_M_singular()) 40 return false; 41 if (__n == 0) 42 return true; 43 if (__n < 0) 44 { 45 std::pair<difference_type, _Distance_precision> __dist = 46 __get_distance(_M_get_sequence()->_M_base().begin(), base()); 47 bool __ok = ((__dist.second == __dp_exact && __dist.first >= -__n) 48 || (__dist.second != __dp_exact && __dist.first > 0)); 49 return __ok; 50 } 51 else 52 { 53 std::pair<difference_type, _Distance_precision> __dist = 54 __get_distance(base(), _M_get_sequence()->_M_base().end()); 55 bool __ok = ((__dist.second == __dp_exact && __dist.first >= __n) 56 || (__dist.second != __dp_exact && __dist.first > 0)); 57 return __ok; 58 } 59 } 60 61 template<typename _Iterator, typename _Sequence> 62 bool 63 _Safe_iterator<_Iterator, _Sequence>:: _M_valid_range(const _Safe_iterator & __rhs) const64 _M_valid_range(const _Safe_iterator& __rhs) const 65 { 66 if (!_M_can_compare(__rhs)) 67 return false; 68 69 /* Determine if we can order the iterators without the help of 70 the container */ 71 std::pair<difference_type, _Distance_precision> __dist = 72 __get_distance(base(), __rhs.base()); 73 switch (__dist.second) { 74 case __dp_equality: 75 if (__dist.first == 0) 76 return true; 77 break; 78 79 case __dp_sign: 80 case __dp_exact: 81 return __dist.first >= 0; 82 } 83 84 /* We can only test for equality, but check if one of the 85 iterators is at an extreme. */ 86 /* Optim for classic [begin, it) or [it, end) ranges, limit checks 87 * when code is valid. Note, for the special case of forward_list, 88 * before_begin replaces the role of begin. */ 89 if (_M_is_beginnest() || __rhs._M_is_end()) 90 return true; 91 if (_M_is_end() || __rhs._M_is_beginnest()) 92 return false; 93 94 // Assume that this is a valid range; we can't check anything else 95 return true; 96 } 97 } // namespace __gnu_debug 98 99 #endif 100 101